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<tr class="t-nv"><td colspan="5"> <a href="decltype.html" title="cpp/language/decltype"><tt>decltype</tt></a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
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</table></div></td></tr>
<tr class="t-nv-h2"><td colspan="5"> Special member functions</td></tr>
<tr class="t-nv-col-table"><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="default_constructor.html" title="cpp/language/default constructor"> Default constructor</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="copy_constructor.html" title="cpp/language/copy constructor"> Copy constructor</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="move_constructor.html" title="cpp/language/move constructor"> Move constructor</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
</table></div></td><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="as_operator.html" title="cpp/language/as operator" class="mw-redirect"> Copy assignment</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="move_operator.html" title="cpp/language/move operator" class="mw-redirect"> Move assignment</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="destructor.html" title="cpp/language/destructor"> Destructor</a></td></tr>
</table></div></td></tr>
<tr class="t-nv-h1"><td colspan="5"><a href="templates.html" title="cpp/language/templates"> Templates</a> </td></tr>
<tr class="t-nv-col-table"><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="class_template.html" title="cpp/language/class template"> Class template </a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="function_template.html" title="cpp/language/function template"> Function template </a></td></tr>
</table></div></td><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="template_specialization.html" title="cpp/language/template specialization"> Template specialization</a></td></tr>   
<tr class="t-nv"><td colspan="5"> <a href="parameter_pack.html" title="cpp/language/parameter pack"> Parameter packs</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
</table></div></td></tr>
<tr class="t-nv-h1"><td colspan="5"> Miscellaneous </td></tr>
<tr class="t-nv-col-table"><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="asm.html" title="cpp/language/asm"> Inline assembly</a></td></tr>
</table></div></td><td><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="history.html" title="cpp/language/history"> History of C++</a></td></tr>
</table></div></td></tr>
</table></div>
</div><div></div></div></div></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><strong class="selflink"> Classes</strong><div class="t-navbar-menu"><div><div style="display:inline-block">
<div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv-h2"><td colspan="5"> General </td></tr>
<tr class="t-nv"><td colspan="5"> <strong class="selflink"> Overview</strong> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="class.html" title="cpp/language/class"> <code>class</code>/<code>struct</code> types</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="union.html" title="cpp/language/union"> <code>union</code> types</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="injected-class-name.html" title="cpp/language/injected-class-name"> Injected-class-name</a> </td></tr>
<tr class="t-nv-h2"><td colspan="5"> Members </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="data_members.html" title="cpp/language/data members">Data members</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="static.html" title="cpp/language/static">Static members</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="this.html" title="cpp/language/this">The <code>this</code> pointer</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="nested_classes.html" title="cpp/language/nested classes" class="mw-redirect">Nested classes</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="member_template.html" title="cpp/language/member template">Member templates</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="bitfield.html" title="cpp/language/bit field">Bit fields</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="using_declaration.html" title="cpp/language/using declaration"><code>using</code>-declarations</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="member_functions.html" title="cpp/language/member functions">Member functions</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="access.html" title="cpp/language/access">Member access specifiers</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="initializer_list.html" title="cpp/language/constructor">Constructors and member initializer lists</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="data_members.html#Member_initialization" title="cpp/language/data members">Default member initializer</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="friend.html" title="cpp/language/friend"><code>friend</code> specifier</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="explicit.html" title="cpp/language/explicit"><code>explicit</code> specifier</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="converting_constructor.html" title="cpp/language/converting constructor">Converting constructor</a></td></tr>
<tr class="t-nv-h2"><td colspan="5"> Special member functions </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="default_constructor.html" title="cpp/language/default constructor">Default constructor</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="copy_constructor.html" title="cpp/language/copy constructor">Copy constructor</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="move_constructor.html" title="cpp/language/move constructor">Move constructor</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="as_operator.html" title="cpp/language/copy assignment">Copy assignment operator</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="move_operator.html" title="cpp/language/move assignment">Move assignment operator</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="destructor.html" title="cpp/language/destructor">Destructor</a></td></tr>
<tr class="t-nv-h2"><td colspan="5"> Inheritance </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="derived_class.html" title="cpp/language/derived class">Base and derived classes</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="ebo.html" title="cpp/language/ebo">Empty base optimization (EBO)</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="virtual.html" title="cpp/language/virtual">Virtual member functions</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="abstract_class.html" title="cpp/language/abstract class">Pure virtual functions and abstract classes</a></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="override.html" title="cpp/language/override"><tt>override</tt></a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="final.html" title="cpp/language/final"><tt>final</tt></a> <span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
</table></div>
</div><div></div></div></div></div><div class="t-navbar-sep"> </div></div>
<p>A class is a user-defined type.
</p><p>A class type is defined by class-specifier, which appears in <span class="t-spar">decl-specifier-seq</span> of the <a href="declarations.html" title="cpp/language/declarations">declaration</a> syntax. See <a href="class.html" title="cpp/language/class">class declaration</a> for the syntax of the class specifier.
</p><p>A class can have the following kinds of members:
</p>
<div class="t-li1"><span class="t-li">1)</span> data members:</div>
<div class="t-li2"><span class="t-li">a)</span> <a href="data_members.html" title="cpp/language/data members">non-static data members</a>, including <a href="bitfield.html" title="cpp/language/bit field">bit-fields</a>.</div>
<div class="t-li2"><span class="t-li">b)</span> <a href="static.html#Static_data_members" title="cpp/language/static">static data members</a></div>
<div class="t-li1"><span class="t-li">2)</span> member functions:</div>
<div class="t-li2"><span class="t-li">a)</span> <a href="member_functions.html" title="cpp/language/member functions">non-static member functions</a></div>
<div class="t-li2"><span class="t-li">b)</span> <a href="static.html#Static_member_functions" title="cpp/language/static">static member functions</a></div>
<div class="t-li1"><span class="t-li">3)</span> nested types:</div>
<div class="t-li2"><span class="t-li">a)</span> <a href="nested_classes.html" title="cpp/language/nested classes" class="mw-redirect">nested classes</a> and <a href="enum_class.html" title="cpp/language/enum">enumerations</a> defined within the class definition</div>
<div class="t-li2"><span class="t-li">b)</span> aliases of existing types, defined with <a href="typedef.html" title="cpp/language/typedef"><code>typedef</code></a> <span class="t-rev-inl t-since-cxx11"><span>or <a href="type_alias.html" title="cpp/language/type alias">type alias</a> </span> <span><span class="t-mark-rev t-since-cxx11">(since C++11)</span></span></span>declarations</div>
<div class="t-li2"><span class="t-li">c)</span> the name of the class within its own definition acts as a public member type alias of itself for the purpose of <a href="unqualified_lookup.html#Injected_class_name" title="cpp/language/unqualified lookup">lookup</a> (except when used to name a <a href="initializer_list.html" title="cpp/language/constructor">constructor</a>): this is known as <i><a href="injected-class-name.html" title="cpp/language/injected-class-name">injected-class-name</a></i></div>
<div class="t-li1"><span class="t-li">4)</span> <a href="enum_class.html" title="cpp/language/enum">enumerators</a> from all unscoped enumerations defined within the class<span class="t-rev-inl t-since-cxx20"><span>, or introduced by <a href="using_declaration.html" title="cpp/language/using declaration">using-declarations</a> or <a href="enum_class.html#Using-enum-declaration" title="cpp/language/enum">using-enum-declarations</a></span> <span><span class="t-mark-rev t-since-cxx20">(since C++20)</span></span></span></div>
<div class="t-li1"><span class="t-li">5)</span> <a href="member_template.html" title="cpp/language/member template">member templates</a> (<span class="t-rev-inl t-since-cxx14"><span>variable templates, </span> <span><span class="t-mark-rev t-since-cxx14">(since C++14)</span></span></span>class templates or function templates) may appear in the body of any non-local class/struct/union.</div>
<p>All members are defined at once in the class definition, they cannot be added to an already-defined class (unlike the members of namespaces)
</p><p>A member of a class <code>T</code> cannot use <code>T</code> as its name if the member is
</p>
<ul><li> a static data member,
</li><li> a member function,
</li><li> a member type,
</li><li> a member template,
</li><li> an enumerator of an <span class="t-rev-inl t-since-cxx11"><span>unscoped</span> <span><span class="t-mark-rev t-since-cxx11">(since C++11)</span></span></span> enumeration, or
</li><li> a member of a member anonymous union.
</li></ul>
<p>However, a non-static data member may use the name <code>T</code> as long as there are no user-declared constructors.
</p><p>A class with at least one declared or inherited <a href="virtual.html" title="cpp/language/virtual">virtual</a> member function is <i>polymorphic</i>. Objects of this type are <a href="objects.html#Polymorphic_objects" title="cpp/language/object">polymorphic objects</a> and have runtime type information stored as part of the object representation, which may be queried with <a href="dynamic_cast.html" title="cpp/language/dynamic cast"><code>dynamic_cast</code></a> and <a href="typeid.html" title="cpp/language/typeid"><code>typeid</code></a>. Virtual member functions participate in dynamic binding.
</p><p>A class with at least one declared or inherited pure virtual member function is an <a href="abstract_class.html" title="cpp/language/abstract class">abstract class</a>. Objects of this type cannot be created.
</p>
 <table class="t-rev-begin">
<tr class="t-rev t-since-cxx11"><td>
<p>A class with a <a href="constexpr.html" title="cpp/language/constexpr">constexpr</a> constructor is a <a href="../named_req/LiteralType.html" title="cpp/named req/LiteralType"><span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">LiteralType</span></a>: objects of this type can be manipulated by <a href="constexpr.html" title="cpp/language/constexpr">constexpr</a> functions at compile time.
</p>
</td>
<td><span class="t-mark-rev t-since-cxx11">(since C++11)</span></td></tr>
</table>
<h3><span class="mw-headline" id="Properties_of_classes">Properties of classes</span></h3>
 <table class="t-rev-begin">
<tr class="t-rev t-since-cxx11"><td>
<h4> <span class="mw-headline" id="Trivially_copyable_class">Trivially copyable class</span></h4>
<p>A <i>trivially copyable class</i> is a class that
</p>
 <table class="t-rev-begin">
<tr class="t-rev t-until-cxx20"><td>
<ul><li> has at least one non-deleted copy constructor, move constructor, copy assignment operator, or move assignment operator
</li><li> each copy constructor is either <a href="copy_constructor.html#Trivial_copy_constructor" title="cpp/language/copy constructor">trivial</a> or deleted
</li><li> each move constructor is either <a href="move_constructor.html#Trivial_move_constructor" title="cpp/language/move constructor">trivial</a> or deleted
</li><li> each copy assignment operator is either <a href="as_operator.html#Trivial_copy_assignment" title="cpp/language/copy assignment">trivial</a> or deleted
</li><li> each move assignment operator is either <a href="move_operator.html#Trivial_move_assignment" title="cpp/language/move assignment">trivial</a> or deleted, and
</li><li> has a non-deleted <a href="destructor.html#Trivial_destructor" title="cpp/language/destructor">trivial destructor</a>.
</li></ul>
</td>
<td><span class="t-mark-rev t-until-cxx20">(until C++20)</span></td></tr>
<tr class="t-rev t-since-cxx20"><td>
<ul><li> has at least one eligible <a href="copy_constructor.html#Eligible_copy_constructor" title="cpp/language/copy constructor">copy constructor</a>, <a href="move_constructor.html#Eligible_move_constructor" title="cpp/language/move constructor">move constructor</a>, <a href="as_operator.html#Eligible_copy_assignment_operator" title="cpp/language/copy assignment">copy assignment operator</a>, or <a href="move_operator.html#Eligible_move_assignment_operator" title="cpp/language/move assignment">move assignment operator</a>,
</li><li> each eligible copy constructor is <a href="copy_constructor.html#Trivial_copy_constructor" title="cpp/language/copy constructor">trivial</a>
</li><li> each eligible move constructor is <a href="move_constructor.html#Trivial_move_constructor" title="cpp/language/move constructor">trivial</a>
</li><li> each eligible copy assignment operator is <a href="as_operator.html#Trivial_copy_assignment" title="cpp/language/copy assignment">trivial</a>
</li><li> each eligible move assignment operator is <a href="move_operator.html#Trivial_move_assignment" title="cpp/language/move assignment">trivial</a>, and
</li><li> has a non-deleted <a href="destructor.html#Trivial_destructor" title="cpp/language/destructor">trivial destructor</a>.
</li></ul>
</td>
<td><span class="t-mark-rev t-since-cxx20">(since C++20)</span></td></tr>
</table>
<p><br>
</p>
<h4> <span class="mw-headline" id="Trivial_class">Trivial class</span></h4>
<p>A <i>trivial class</i> is a class that
</p>
<ul><li> is trivially copyable, and
</li></ul>
 <table class="t-rev-begin">
<tr class="t-rev t-until-cxx20"><td>
<ul><li> has one or more default constructors, all of which are either <a href="default_constructor.html#Trivial_default_constructor" title="cpp/language/default constructor">trivial</a> or deleted and at least one of which is not deleted.
</li></ul>
</td>
<td><span class="t-mark-rev t-until-cxx20">(until C++20)</span></td></tr>
<tr class="t-rev t-since-cxx20"><td>
<ul><li> has one or more <a href="default_constructor.html#Eligible_default_constructor" title="cpp/language/default constructor">eligible default constructors</a>, all of which are <a href="default_constructor.html#Trivial_default_constructor" title="cpp/language/default constructor">trivial</a>.
</li></ul>
</td>
<td><span class="t-mark-rev t-since-cxx20">(since C++20)</span></td></tr>
</table>
<p><br>
</p>
<h4> <span class="mw-headline" id="Standard-layout_class">Standard-layout class</span></h4>
<p>A <i>standard-layout class</i> is a class that
</p>
<ul><li> has no <a href="data_members.html" title="cpp/language/data members">non-static data members</a> of type non-standard-layout class (or array of such types) or reference,
</li><li> has no <a href="virtual.html" title="cpp/language/virtual">virtual functions</a> and no <a href="derived_class.html#Virtual_base_classes" title="cpp/language/derived class">virtual base classes</a>,
</li><li> has the same <a href="access.html" title="cpp/language/access">access control</a> for all non-static data members,
</li><li> has no non-standard-layout base classes,
</li><li> has all non-static data members and <a href="bitfield.html" title="cpp/language/bit field">bit-fields</a> in the class and its base classes first declared in the same class, and
</li><li> given the class as S, has no element of the set M(S) of types as a base class, where M(X) for a type X is defined as:
</li></ul>
<dl><dd><ul><li> If X is a non-union class type with no (possibly inherited) non-static data members, the set M(X) is empty.
</li><li> If X is a non-union class type whose first non-static data member has type X0 (where said member may be an anonymous union), the set M(X) consists of X0 and the elements of M(X0).
</li><li> If X is a union type, the set M(X) is the union of all M(Ui) and the set containing all Ui, where each Ui is the type of the ith non-static data member of X.
</li><li> If X is an array type with element type Xe, the set M(X) consists of Xe and the elements of M(Xe).
</li><li> If X is a non-class, non-array type, the set M(X) is empty.
</li></ul>
</dd></dl>
<p><br>
A <i>standard-layout struct</i> is a standard-layout class defined with the class keyword <a href="../keyword/struct.html" title="cpp/keyword/struct"><tt>struct</tt></a> or the class keyword <a href="../keyword/class.html" title="cpp/keyword/class"><tt>class</tt></a>. A <i>standard-layout union</i> is a standard-layout class defined with the class keyword <a href="../keyword/union.html" title="cpp/keyword/union"><tt>union</tt></a>.
</p>
</td>
<td><span class="t-mark-rev t-since-cxx11">(since C++11)</span></td></tr>
</table>
<p><br>
</p>
 <table class="t-rev-begin">
<tr class="t-rev t-since-cxx20"><td>
<h4> <span class="mw-headline" id="Implicit-lifetime_class">Implicit-lifetime class</span></h4>
<p>An <i>implicit-lifetime class</i> is a class that
</p>
<ul><li> is an <a href="aggregate_initialization.html" title="cpp/language/aggregate initialization">aggregate</a>, or
</li><li> has at least one trivial eligible constructor and a trivial, non-deleted destructor.
</li></ul>
</td>
<td><span class="t-mark-rev t-since-cxx20">(since C++20)</span></td></tr>
</table>
<p><br>
</p>
 <table class="t-rev-begin">
<tr class="t-rev t-until-cxx20"><td>
<h4> <span class="mw-headline" id="POD_class">POD class</span></h4>
<p>A <i>POD class</i> is a class that
</p>
 <table class="t-rev-begin">
<tr class="t-rev t-until-cxx11"><td>
<ul><li> is an <a href="aggregate_initialization.html" title="cpp/language/aggregate initialization">aggregate</a>,
</li><li> has no user-declared copy assignment operator,
</li><li> has no user-declared destructor, and
</li><li> has no non-static data members of type non-POD class (or array of such types) or reference.
</li></ul>
</td>
<td><span class="t-mark-rev t-until-cxx11">(until C++11)</span></td></tr>
<tr class="t-rev t-since-cxx11"><td>
<ul><li> is a trivial class,
</li><li> is a standard-layout class, and
</li><li> has no non-static data members of type non-POD class (or array of such types).
</li></ul>
</td>
<td><span class="t-mark-rev t-since-cxx11">(since C++11)</span></td></tr>
</table>
<p><br>
A <i>POD struct</i> is a non-union POD class. A <i>POD union</i> is a union that is a POD class.
</p>
</td>
<td><span class="t-mark-rev t-until-cxx20">(until C++20)</span></td></tr>
</table>
<h3><span class="mw-headline" id="Defect_reports">Defect reports</span></h3>
<p>The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
</p>
<table class="dsctable" style="font-size:0.8em">
<tr>
<th> DR
</th>
<th> Applied to
</th>
<th> Behavior as published
</th>
<th> Correct behavior
</th></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/148.html">CWG 148</a>
</td>
<td> C++98
</td>
<td> POD classes could not contain pointers to member,<br>which are themselves POD (scalar) types
</td>
<td> restriction removed
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/383.html">CWG 383</a>
</td>
<td> C++98
</td>
<td> copy assignment operators or destructors could be<br>user-declared in POD classes if they are not defined
</td>
<td> not allowed
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1363.html">CWG 1363</a>
</td>
<td> C++11
</td>
<td> a class that has both trivial default constructors and non-trivial<br> default constructors at the same time could be trivial
</td>
<td> it is non-trivial
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1496.html">CWG 1496</a>
</td>
<td> C++11
</td>
<td> a class that only has constructors that<br>are all defined as deleted could be trivial
</td>
<td> it is non-trivial
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1672.html">CWG 1672</a>
</td>
<td> C++11
</td>
<td> a class could be a standard-layout class<br>if it has multiple empty base classes
</td>
<td> it is not a standard-layout class
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1734.html">CWG 1734</a>
</td>
<td> C++11
</td>
<td> a trivially copyable class could not have non-trivial<br>deleted copy/move constructors/assignment operators
</td>
<td> can be trivial if deleted
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1813.html">CWG 1813</a>
</td>
<td> C++11
</td>
<td> a class was never a standard-layout class if it has a<br>base class that inherits a non-static data member
</td>
<td> it can be a standard-layout class
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1881.html">CWG 1881</a>
</td>
<td> C++11
</td>
<td> for a standard-layout class and its base classes,<br>unnamed bit-fields might be declared in a<br>different class declaring the data members
</td>
<td> all non-static data members<br>and bit-fields need to be first<br>declared in the same class
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/1909.html">CWG 1909</a>
</td>
<td> C++98
</td>
<td> a member template could have the same name as its class
</td>
<td> prohibited
</td></tr>
<tr>
<td> <a rel="nofollow" class="external text" href="https://cplusplus.github.io/CWG/issues/2120.html">CWG 2120</a>
</td>
<td> C++11
</td>
<td> the definition of M(X) in determining a standard-<br>layout class did not consider the case of<br>a class whose first member is an array
</td>
<td> addressed this case in<br>the definition of M(X)
</td></tr></table>

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